I'll chime in here too... I had a similar occurrence yesterday while commuting. I was following a guy weaving all over the road. He swung into the other lane several times. It was obvious that he was going to travel a great distance (there aren't many turn-off's on this road), so it wasn't a matter of keeping an eye on him for only a few blocks before he turned into the driveway.

I called 911. I don't care if he takes himself out, but anyone in oncoming traffic would not have had a chance. They would have been in a very undeserved head-on collission through no fault of their own - almost happened in one case. Think of the injury, the property loss, etc. I really didn't like to do it, but then I thought that I would appreciate it if someone called in a drunk driver rather than have him bash into ME. I see no difference in your situation, except in the mode of transportation.

No one wants to be a bad guy and today, especially me. Too many people don't want to 'get involved'. But they'll appreciate it if someone else does it for them. If your motive was just to get this guy into trouble, that would be one thing. But to protect someone who's giving rides to people who are presuming that he's properly trained and licensed is quite another thing. It's a hard choice.

Just my $.02

Bob